Fusion protein for immunocastration (Sequences 1a and 1b) that comprises the primary amino acid sequence of the gonadotrophin-liberating protein fused to a theoretical sequence: Sequence 1a NH 2 - QHWSYGLRPG GPPFSGGGGPPFSA-COOH Sequence 1b NH 2 -GPPFSGGGGPPFSA QHWSYGLRPG-COOH； DNA sequences coding for said fusion protein； vaccine comprising said fusion protein； use of the fusion protein for mammal immunocastration； process for producing the vaccine； process for preparing the fusion protein that comprises fusing the amino acid sequence of the gonadotrophin-liberating hormone (GnRH-I) to a theoretical glycosilable sequence having immunogenic activity that does not include pathogen or "carrier" protein sequences in its structure.
